Dual belt tightener



lM'u'ch 3, 1959 E. NIEDERER ETAL,

DUAL BELT TIGHTENER Filed May 7, 1957 5 Sheets-Sheet 1 lll March 3,'` 1959 E. Nn-:DERER Erm. 2,875,626

DUAL BELT TIGHTENER Filed May '1, 1957 5 Sheets-Sheat 2 @defer Sep f1.7 Zazie/# y En es afm 0 l?? i E. NIEDERER. ErAL 2,875,626

March 3, 1959 DUAL BELT TIGHTENER s sheetssheet s Filed May 7, 1957 United States Patent Oii i 2,875,626 Patented Mar. 3, 1959 ice DUAL BELT TIGHTENER Ernest Niederer, Elmhurst, and

cago, lll., assignors to Refrigeration Appliances, Inc., Chicago, Ill., a corporation of Illinois Application May 7, 1957, Serial No. 657,592 Claims. (-Cl. 74-242.13)

This invention relates to a belt tightener in which a shaft, to or from which power is supplied by a belt, is adjustable sidewise in two directions transverse to one another to regulate the tension of the belt, the invention being particularly adapted for dual belt tightening purposes to insure equalized tension of two belts which lead divergently to devices at opposite sides of the shaft for transmitting power thereto or therefrom.

More particularly the invention is adapted to provide a mounting for a motor by which two devices are operable by separate belts trained around the motor shaft, and to permit the motor to be adjusted to an intermediate position, determined by the belts, in which the tension of the two belts is the same.

To this end the motor mounting or support is located at a place between the driven shafts to which power is to be transmitted from the motor, and at a distance below the level of the driven shafts so that the two belts extend upwardly and outwardly in opposite directions from the motor shaft in divergent relation to one another, and the motor mounting is pivotally supported to swing sidewise, in the direction of separation of the two driven shafts from one another, so as to assume a position determined by the two belts and the mounting is also pivoted to swing with the motor thereon to higher and lower elevations so that the weight thereof is supported coniointly by the two belts.

Thus the two belts are somewhat like two toggle arms or levers with the combined motor mounting and motor carried at the place where the two arms are pivoted to one another, and the combinedv motor mounting and motor, by reason of the pivoted support thereof, which permits sidewise movement thereof, and by reason of the pivotal movement thereof, which permits swinging thereof to higher and lower elevations, are free to assume an intermediate position which the belts themselves determine when they are both outstretched and taut.

With this construction the Weight of the combined motor mounting and motor is supported by the two belts and in some cases the driven devices may be operated by the motorwhile the latter is thus supported and free to swing sidewise and up and down, in which event the tension of the two belts is constantly maintained solely by the combined weight of the motor mounting and the motor. It is preferred, however, to utilize such weight, and additional helping pressure if desired, to obtain the desired belt tension and then lock the motor mounting and motor in the position of belt tension as thus determined.

The principal objects of this invention are to provide an improved belt tightener which is usable to tighten two oppositely inclined or divergent belts conjointly and equally; to accomplish such belt tightening with a device which is simple, convenient and inexpensive; to construct the belt tightener from standard or stock materials without requiring complicated'or expensive parts which are not readily available; to insureaccurate location of the common drive shaft for positively equalized belt ten- Joseph R. Zwickl, Chi- 5 sion; and to provide simple facilities for locking the common drive shaft in the ascertained positions of equalized belt tension, these and other objects being ac complished as pointed out more particularly hereinafter and as shown in the acompanying drawing, in which:

Fig. 1 is a front view, with parts broken away, of a double-fan air conditioning unit in which a dual tightener is employed which is made in accordance with the present invention;

Fig. 2 is an enlarged vertical sectional view of the air conditioner of Fig. l taken substantially on the line 2--2 of Fig. l;

Fig. 3 is an enlarged horizontal sectional view of the air conditioner of Figs. l and 2 taken on the line 3--3 of Fig. 2;

Fig. 4 is an enlarged plan view of the belt tightener of Figs. l, 2 and 3 and the associated motor;

Fig. 5 is a vertical sectional view taken substantially along the line 5 5 of Fig. 4;

Fig. 6 is a view similar to Fig. 5 and showing the belt tightener in a dilerent position of adjustment;

Fig. 7 is a vertical sectional view taken substantially along line 7-7 of Fig. 6, and

Fig. 8 is a fragmentary perspective view illustrating the head of the clamping bolt that is used in securing the tightener in its adjusted position.

The belt tightener of the present invention has been designed particularly for use in connection. with air conditioning units of double fan type and is shown herein as applied to such unit, although it is not necessarily limited thereto, and this illustrated unit comprises an elongated rectangular housing 10 which has a refrigerating coil 11 mounted in the rear entrance thereto. At the front thereof the housing is provided with two laterally spaced openings 12 each having a short rectangular hood 13 extending forwardly therefrom and screened at the forward end as indicated at 14.

A pair of air impeller fans 15.are mounted respectively at the rear ends of the hoods 13 to discharge therethrough andthese fans are operated fromV a common electric motor 16 with which the belt tightener of the present invention is associated. In fact, the motor is a part of the belt tightener as the fans 15 are operated by two separate belts from sheaves on the shaft of the motor 16 and the motor is supported on a mounting which permits movement of the motor and its shaft by which the belt tightening is accomplished. Thus the motor and motor mounting constitute the belt tightening facilities.

Each fan 15 is secured to the forward end of a separate shaft 17 which is journaled in a pair of bearings 18 which are mounted on the bottom web 19 of a channel shaped boot 20 which has wings 21 at the opposite sides which are secured respectively to a pair of laterally spaced angle iron nprights 22 which are in turn secured at their upper and lower ends to frame members 23 of the housing 10 at the top and bottom thereof.

A brace 24 which extends from end to end of the housing 10 and is secured at its opposite ends to frame members 25 of the housing, is located approximately midway between the top and bottom of the housing and at the rear of and secured to the uprights 22, and the rear one of each pair of bearings 18 is directly above this brace 24 and secured thereto through the bottom web 19 of the respective channel shaped boot 20.

The motor 16, which is located approximately midway between but at a lower level than the fan shafts 17, is secured by bolts 26 to a platform 27 which is provided at one end with a riser portion 28 which extends upwardly from the platform 2.7 lat one side of the motor and is pivoted at its upper end on a 'bolt or pin 29 which extends through the upper ends of the side flanges30 of an upright rocker plate 31.

-This .rocker plate 31 is `in turn pivoted at its lower end -to a-base plate 32 lby a bolt or pin 33 which extends through upwardly extending side flanges 34 of the lbase plate 32 and through the lower ends of the side flanges '30 off'the Lrocker plate 31. The-base plate-32 4is secured to the bottom of the housing" inl aV fixed position and preferably has upturned flanges-35 at its ends (see Fig. l) which are secured to housing frame members 36 which extend from front to rear of the housing and both o f the pivot bolts or pins 29'arid 33 are parallel with the shaft 37 of the' motor and the motor shaft 37 is parallel w-ith the fan shafts 17.

The platform 27, rocker plate 31 and base plate 32 are convenient-ly and inexpensively made of sheet metal, the rocker plate 31 merely being bent at suitable laterally spaced apart places to provide the two side Iflanges 30, and -the base plate 32 being bent at suitable laterally spaced places to provide `the two upwardly extending side flanges 3 4 which will accommodate the lower end of the rocker plate 31 therebetween and said base plate also having the end flanges 35 ybent upwardly therefrom.

The' platform 27 and riser ,28 are formed from a plate which is bent along a transverse line so that the riser 28 extends at right angles to the platform and the platform 27 has downturned flanges 38 at the opposite side extremities thereof and is of a width to be accommodated between the side flanges 34 of the base plate 32 and the riser has outturned flanges 39 at the opposite side extremities and is of a width to be accommodated between the side flanges 30 of the rocker plate 31 and the flanges 39 have the bolt or pin 29 extending through the upper ends thereof.

The combination platform 27 and riser 28 is preferably of .sufficiently heavy sheet metal or plate stock so that the side flanges thereof may be cut away as at 40 to facilitate `bending and without impairing the required strength -at this place, and the platform 27 may have a downturned flange 41 at its outer end and the riser may have an outturned flange 42 at its upper end.

Two sheaves 43 or a double sheave, are provided on the motor shaft 37 which are connected respectively by two belts 44 to sheaves 4S which are secured respectively to the fan shafts 17 so that the two fans are operated conjointly by the motor 16, and when thus connected and if the platform 27 is free to swing on the elevated pivot pin 29 and the rocker plate 31 is free to swing on the pivot pin 33, the motor 16 and platform will be supported by the two 'belts and -by reason of the oppositely inclined directions in which the two belts extend upwardly and outwardly from the motor the weight of the motor will cause the rocker plate 31 to swing sidewise on the pivot pin 33 and the platform 27 to swing downwardly on the pivot pin 29 to a position determined by the conjoint action of the two belts 44, and in this position the belts will bot-h be outstretched at a tension imposed thereon by the weight of the motor 16. Y

l lf the fan shafts 17 are at the same elevation, as shown herein, and the belts 44 are of the same length, as shown herein, the motor will assume a position in which the shaft 37 thereof is in a plane midway between the shafts 17, and the `belts 44 will sustain equally the weight of the motor and the tension thereof will be the same.

The fans may be operated by the motor while the latter is supported solely by the belts 44 in which event the motoroccupies what maybe considered a floating position in which the tension of the belts is constantly maintained by the weight of the motion, but it is preferred to lock the platform 27 and the motor in a position of belt tension as determined by the weight of the motor, supplemented lby hand pressure if desired, so that the motor is held in a fixed position ofpreadjusted belt tension when the motor is operated to rotate the fans. For this purpose each of the base plate flanges 34 has a plate 46 secured thereto and projecting upwardly thereabove as shown particularly in Figs. 5, 6 and 7 at opposite sides respectively of and close to the platform 27 near the outer end thereof, and these plates have corresponding vertical slots 47, and the platform Aflanges 38 have slots 48 extending transversely to the slots 47 and cooperable therewith to receive a clamping bolt 49 therethrough with wing ynut 50 on the end thereof by which the platform may `be rigidly secured in various positions of adjustment of ythe tension of the belts 44.

This belt 49 has a spacer tube 51 thereon between the platform flanges 38 and washers 52 are provided on the bolt 49 between the flanges 38 and, `the fixed plates 46 to insure clamping effect when the wing nut is tightened, and the -bolt head is preferably for-med as shown in Fig. 8 with a ri'b or key 53 on the inner side which fits in the slot 47 of the adjoining plate 46 to prevent turning of the bolt.

When the Wins out 50 .is loosened, .they the platform 27 with motor thereon is free to swing on Vthe pivot 29 by reason of the slots 47 and is also free to move in the direction ofthe length of the platform by reason of the slots 48 and the rockability of the roclihrlgplate 31 on the pivot 33 and thus the motor may be `adjusted by the weight thereof and added hand pressure if desired to impose the required tension on the belts 44 whereupon the wing nut 50 is tightened to lock the platform 27 and motor 16 in the thus adjusted position to lmaintain the 'belt tension provided by such adjustment. Y

Belts of forms other than that disclosed herein may be employed, such for example as link belts, and the belts need not necessarily be of the same length nor the shafts 1'7 at the same elevation, and the devicemay be employed for tightening a single belt, although the arrangement shown and described herein is the preferred form.

While I have shown and described my invention in a preferred form, and the invention is particularly adapted to two belt tightening for the reason explainedalve, the invention or certain features thereof may be advantageously employed in connection with other belt tightening devices and various changes and modifications may be made without departing from the prineiples o f the invention, the scope of which is to be determined by the appended claims.

What is claimed is:

1. A device of the `class described comprising a base, a motor having a shaft extending therefrom, a pair of laterally spaced shafts which are operable by and rotatably mounted at an elevation above the motor at opposite sides respectively thereof and have a pair of belts extending respectivelyvtherefrom downwardly in convergent relationship to one another to the motor Shaft, the base being provided with means extending upwardly therefrom which supports a pivot at one side of the motor and the motor being detachably secured to a motor holder which extends underneath the motor and is suspended at one end from said pivot for freedom of conjoint suspension of the motor by said pair of belts, and means on the base for securing the motor in such suspended position.

2. A device in accordance with claim 1 wherein said pivot from which the motor holdery is suspended is carried by a swinging linl.

3. A devie in accordance with claim l wherein. the means which extends upwardly from the base is pivoted at its lower end to the base.

4. A device in accordance with claim l wherein the means which extends upwardly from the base is pivoted at its lower end to the base and the motor holder has an upturnod portion at its Said ono ond and Said upturned portion engages said pivot.

5. A device in accordance with claim l wherein the means which extends upwardly from the base is an upwardly extending plate having reinforcing flanges at its 5 opposite lateral extremities through which said pivot extends, and the motor holder is a plate which extends laterally from said upwardly extending plate of said means and has an upturned portion with reinforcing flanges through which said pivot extends.

6 References Cited in the file of this patent UNITED STATES PATENTS Bechaud Aug. 14; 192

FOREIGN PATENTS Great Britain Feb. 2, 1949 

